JP3896911B2 - Both tab cells and batteries - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tab-type cell that is a sheet-like thin battery and an assembled battery formed by stacking the cells.
[0002]
[Prior art]
A thin battery disclosed in Japanese Patent Laid-Open No. 9-259859 is known as a both-tab type cell (hereinafter also referred to as a thin battery) from which sheet-like positive electrode tabs and negative electrode tabs are drawn from both ends. Such a tab-type cell includes a positive electrode foil (referred to as a positive electrode) coated with a positive electrode active material on both sides and a negative electrode foil (referred to as a negative electrode) coated with a negative electrode active material on both sides. A plurality of internal electrode pairs laminated via a separator are stacked, and the plurality of internal electrode pairs are immersed in an electrolyte solution and sealed with an exterior material, and the positive electrode foil and the negative electrode foil of each layer are respectively connected to the positive electrode tab and the negative electrode. Bonded to the tab, the positive electrode tab and the negative electrode tab are projected from the exterior material. In order to obtain a high-voltage, high-capacity battery using these cells, it is necessary to form a battery pack by connecting a plurality of cells in series or in parallel.
[0003]
[Problems to be solved by the invention]
In the above-described assembled battery, it is necessary to detect the voltage and temperature of each cell when used. In the conventional both-tab type cell described above, the positive electrode tab and the negative electrode tab face in opposite directions. Therefore, when the voltage detection line is routed from the positive and negative electrode tabs, it is necessary to route the voltage detection line on both sides of both tab type cells, which is a factor that hinders the downsizing of the assembled battery.
[0004]
The present invention provides both tab type cells in which detection lines for detecting a cell voltage can be concentrated on one side of the cell, and an assembled battery in which a plurality of them are stacked.
[0005]
The present invention also provides a double tab type cell in which a cell temperature detector can be provided inside the cell, and an assembled battery in which a plurality of the tab type cells are stacked.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, an internal electrode pair in which a positive electrode and a negative electrode are laminated and an electrolytic solution are formed by joining together flanges provided on the entire circumference of a film-like upper exterior material and lower exterior material. A tab-type cell that is accommodated in the bag-shaped exterior material and has a positive electrode tab and a negative electrode tab connected to the internal electrode pair extending in opposite directions to the exterior of the exterior material, A voltage detection terminal that detects the voltage of a tab having a polarity opposite to that of the tab on one side is provided on at least one of the sides, and the voltage detection line with one end connected to the voltage detection terminal is moved up and down. It is characterized in that the wiring is sandwiched between the joining flanges of the exterior material, and the other end of the voltage detection line is joined to a portion having the same potential as that of the reverse polarity tab .
The invention according to claim 2 is formed by joining an internal electrode pair in which a positive electrode and a negative electrode are laminated, and an electrolytic solution by joining together flanges provided on the entire circumference of the film-like upper exterior material and lower exterior material. A tab-type cell which is accommodated in the bag-shaped exterior material and has a positive electrode tab and a negative electrode tab connected to the internal electrode pair extending in opposite directions to the exterior of the exterior material, one end of the exterior cell A positive voltage detection line that is connected to the same potential as the positive electrode tab inside the body, the other end is sandwiched between the flanges of the upper and lower exterior materials and wired to the negative electrode tab side, and one end is the same as the negative electrode tab inside the exterior body It has a negative voltage detection line connected to a potential portion and having the other end sandwiched between flanges of the upper and lower exterior materials and wired to the positive electrode tab side.
The assembled battery according to claim 4 , wherein the plurality of both tab-type cells, a housing that houses the plurality of stacked tab-type cells, and the plurality of stacked tab-type cells are electrically connected within the housing. A bus bar, a positive external terminal connected to the bus bar that outputs the maximum voltage, a negative external terminal connected to the bus bar that outputs the minimum voltage, and a voltage detection And an external detection terminal to which a terminal or a temperature detection terminal is connected.
[0007]
【The invention's effect】
According to the present invention, since the detection signal lines for detecting the cell voltage are concentrated and routed on one side of the cell, it is possible to suppress an increase in the size of the housing that accommodates the cell. In addition, it is easy to route the signal line between the detection external terminal and the detection internal terminal provided in the housing that accommodates the cell .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
-First embodiment-
Hereinafter, with reference to FIG. 1 to FIG. 6, a first embodiment of a both-tab type cell according to the present invention will be described.
1 to 6 are diagrams for explaining one tab-type cell 1. 1 is a top view of both tab-type cells 1, FIG. 2 is a side view, FIG. 3 (a) is an enlarged sectional view of a portion indicated by reference numeral III in FIG. 2, and FIG. 3 (b) is a further enlarged view of the portion. 4 is a view showing the inside of the tab-type cell 1 with the upper exterior material removed, FIGS. 5A to 5D are cross-sectional views of the tab-type cell 1, and FIG. It is a perspective view which shows an example which concentrates a voltage detection line on the one side of a cell, and is drawn.
[0009]
Both tab type cells 1 are sheet-like lithium ion secondary batteries. The flexible bag-shaped exterior material 100 is formed by thermally welding an upper exterior material 100U having a joint flange 100FU on the entire periphery and a lower exterior material 100L having a joint flange 100FL on the entire periphery at a flange joint (heat seal portion) 103. It is a sealed container. Inside the bag-shaped exterior material 100, an internal electrode pair 101 and an electrolytic solution 102 are accommodated in a vacuum-sealed state. The internal electrode pair 101 includes a sheet-like positive electrode 101a and a negative electrode 101b.
[0010]
As shown in FIG. 3B, the positive electrode 101a is obtained by laminating a positive electrode active material 104a on both surfaces of a positive electrode current collector (positive electrode foil) 104 made of aluminum foil. On the other hand, the negative electrode 101b is obtained by laminating a negative electrode active material 105a on both surfaces of a negative electrode current collector (negative electrode foil) 105 made of copper foil. The positive electrode 101a and the negative electrode 101b are alternately stacked via the separator 101c. These laminates constitute the internal electrode pair 101 described above.
[0011]
As shown to Fig.3 (a), the negative electrode foil 105 of the negative electrode 101b is each connected with the negative electrode tab 1c. The negative electrode tab 1 c penetrates the heat seal portion 103 (see also FIG. 2) of the bag-shaped exterior material 100 in an airtight manner and is fixed to the heat seal portion 103. Although not shown, the positive electrode tab 1b is the same as the negative electrode tab 1c, and the positive electrode foil 104 of the positive electrode 101a is connected to the positive electrode tab 1b.
[0012]
The bag-shaped exterior material 100 is formed of a laminate film having a three-layer structure including an inner surface layer 100a, an intermediate layer 100b, and an outer surface layer 100c. For the inner surface layer 100a, a thermoplastic resin excellent in electrolytic solution resistance and heat sealability such as polyethylene, polypropylene, and polyamide is used. For the intermediate layer 100b, a metal foil having excellent flexibility and strength, such as an aluminum foil or a stainless steel foil, is used. For the outer surface layer 100c, an insulating resin excellent in electrical insulation such as a polyamide-based resin or a polyester-based resin is used.
[0013]
As shown in FIGS. 1 and 4, the features of both the tab-type cells 1 of the first embodiment are that voltage detection terminals 11b and 11c are provided alongside the positive and negative electrode tabs 1b and 1c, and the positive and negative electrodes The point is that the detection lines 12b and 12c between the foils 104 and 105 and the detection terminals 11b and 11c are wired between the flanges 100FU and 100FL.
[0014]
That is, a joining tab 13c is provided at one end of the negative electrode detection line 12c, and is joined to the negative foil 105 via the joining tab 13c. The other end of the negative electrode detection line 12c is provided with a detection terminal 11c in which a hole to be screw-coupled to the external connection portion is formed, and the detection terminal 11c protrudes from the exterior material 100. As shown in FIGS. 5B and 5D, the detection line 12c is sandwiched between the flanges 100FU and 100FL and routed in the battery longitudinal direction. The same applies to the positive electrode detection line 12b. That is, one end of the positive electrode detection line 12b is bonded to the positive electrode foil 104 via the bonding tab 12b. The other end of the positive electrode detection line 12b is provided with a detection terminal 11b in which a hole to be screw-coupled to the external connection portion is provided. The detection terminal 11b protrudes from the exterior material 100.
[0015]
When the above-described double tab type cell 1 is used as a secondary battery of an electric vehicle or a hybrid vehicle, as shown in FIG. 6A, for example, a plurality of flat plate type double tab type cells 1-1 to 1-8 are provided. Lamination is performed via the cell fixing plate 120. Then, as shown in FIG. 6B, cells 1-1, 1-2, 1-5, 1-6 and cells 1-3, 1-4, 1-7, 1-8 are provided by bus bars (not shown). Are connected in parallel to form a parallel battery, and a plurality of parallel batteries are connected in series to output a high voltage. These stacked tab-type cells 1 are accommodated in a casing. A positive external terminal connected to the bus bar that outputs the maximum voltage and a negative external terminal connected to the bus bar that outputs the minimum voltage are provided on the outer surface of the housing. An external voltage detection terminal connected to the voltage detection terminal with a lead wire (harness) is also provided.
[0016]
As shown in FIG. 6A, when a plurality of cells 1 are stacked so that a positive electrode terminal and a negative electrode terminal appear alternately for each parallel battery in the stacking direction on one side of the cell, Since the positive voltage detection terminal 11b and the negative voltage detection terminal 11c are provided on both sides, the voltage detection lines 15b and 15c can be concentrated on one side of the cell.
[0017]
That is, in the first and second stages, positive and negative voltage detection lines 15b and 15c are connected to the negative electrode tab 1c and the positive voltage detection terminal 11b, respectively. In the third and fourth stages, the positive electrode tabs are connected. Positive and negative voltage detection lines 15b and 15c are connected to 1b and negative voltage detection terminal 11c, respectively. These voltage detection lines 15b and 15c are bundled and drawn from the inside of the housing to the outside of the housing, and are connected to a connector which is an external voltage detection terminal provided on the outer surface of the housing. Then, by connecting this connector to a control circuit such as a battery controller, the voltage of each cell is detected by the battery controller.
[0018]
Thus, according to the both tab type cell of 1st Embodiment, the following effects are obtained.
(1) Since the voltage detection terminals 11b and 11c are provided in the flange portions 100FU and FL of the cell 1 along with the positive and negative electrode tabs 1b and 1c, both the tab-type cells are arranged with the positive electrode tab and the negative electrode tab opposite to each other. Even in an assembled battery configured by stacking, the voltage detection lines 15b and 15c can be concentrated and routed to either one of the positive and negative electrode tabs. This leads to a reduction in the size of the assembled battery and simplification of wiring, thereby reducing costs.
(2) When the voltage detection line is routed from both sides of the positive and negative electrode tabs, it is necessary to route the voltage detection line on one side of the cell to the other side of the cell and bundle the voltage detection lines on one side of the cell. For this reason, the voltage detection line must be drawn from between the cells to the opposite side. At this time, the voltage detection line may be caught between the cell fixing plates. In this regard, in the cell of one embodiment, the positive and negative voltage detection lines 15b and 15c can be connected to the tab and the voltage detection terminal on one side of the stacked cells. As a result, it is possible to concentrate the voltage detection lines on one side of the cell and eliminate the possibility of biting into the cell fixing plate.
(3) The detection lines 12b and 12c between the positive and negative electrode tabs 1b and 1c and the detection terminals 11b and 11c are wired between the flanges 100FU and 100FL. Therefore, the detection line routing portion between the flange joint surfaces provides resistance when water enters from the flange joint surface.In other words, the flange joint length in the water intrusion direction can be increased, and moisture from the outside to the cell interior can be increased. Intrusion can be effectively suppressed.
[0019]
FIG. 7A shows a first modification of the first embodiment. In the first embodiment, positive and negative voltage detection terminals 11b and 11c are provided at both ends of the cell. Instead of this, as shown in FIG. 7A, only the positive electrode voltage detection terminal 11b may be provided on the negative electrode tab 1c side on the cell side. This is effective when the direction of the positive and negative electrode tabs is the same in all stages when a plurality of cells are stacked. Although not shown, only the negative electrode voltage detection terminal may be provided on the positive electrode tab 1b side on one side of the cell.
[0020]
FIG. 7B shows a second modification of the first embodiment. In the first embodiment, the joining tabs 13b and 13c and the detection terminals 11b and 11c are provided at both ends of the detection lines 12b and 12c. Instead, thin plate-like detection lines 112b and 112c may be used as shown in FIG. In this case, the detection line end portions 113b and 113c inside the battery are directly welded to portions having the same potential as the positive and negative electrode tabs 1b and 1c, and the end portions 111b and 111c outside the battery are welded to voltage detection lines (not shown).
[0021]
-Second Embodiment-
A second embodiment will be described with reference to FIGS. 8 is a plan view of both tab type cells 50, FIG. 9 is a view showing the inside of the tab type cells 50 with the upper exterior material removed, and FIGS. 10 (a) to 10 (d) are cross-sectional views of the respective parts of both tab type cells 50. FIG.
[0022]
As shown in FIGS. 8 and 9, the two-tab type cell 50 of the second embodiment is characterized in that a thermistor (temperature detector) 70 is provided inside the battery, and two + −detection lines 71 a of the thermistor 70 are provided. , 71b between the flanges 100FU and 100FL and wiring, and the temperature detection terminal 72 is provided along with the negative electrode tab 1c.
[0023]
That is, the thermistor 70 that detects the temperature of the battery 50 is welded to the positive foil 104 inside the exterior material 100, the signal detection lines 71 a and 71 b of the thermistor 70 are routed to the negative electrode tab 1 c side, and the detection that is drawn to the exterior material 100 is performed. A temperature detection terminal 72 is provided at the tip of the wires 71 and 71b. A temperature signal can be taken out from the temperature detection terminal 72. As shown in FIGS. 10B and 10D, the detection lines 71a and 71b are sandwiched between the flanges 100FU and 100FL and routed in the battery longitudinal direction. Note that when the signal detection lines 71a and 71b are covered with vinyl, the vinyl cover may be melted by heat welding of the flanges. Therefore, it is necessary to wire the signal lines 71a and 71b sufficiently apart.
[0024]
As described above, the tab-type cells 50 of the second embodiment can also be stacked by the stacking method shown in FIG. In this case, when temperature detectors are provided in all cells, temperature detection terminals corresponding to the number of cells are provided, and lead wires are connected to the temperature detection terminals. Then, the lead wires are bundled, and the inside of the casing is routed and connected to the temperature detection external terminal outside the casing. This temperature detection external terminal is also connected to the battery controller in the same manner as the voltage detection external terminal described above.
[0025]
According to such a cell 50 and an assembled battery, the following effects can be obtained.
(1) Since the thermistor 70 is joined to the positive electrode foil 104 inside the battery and a temperature-dependent signal is taken out from the temperature detection terminal 72 outside the cell, the assembled battery is compared with the case where a temperature detector is provided outside the cell. Is miniaturized.
(2) Since the thermistor 70 is provided inside the cell, the temperature of the cell can be accurately detected without providing a temperature sensor on the outer surface of the exterior material.
(3) The temperature detection lines 71a and 71b between the thermistor 70 and the temperature detection terminal 72 are wired between the flanges 100FU and 100FL. Therefore, the detection line routing portion between the flange joint surfaces serves as resistance when water enters from the flange joint surface, and the intrusion of moisture can be effectively suppressed. In the second embodiment, since the two detection lines 71a and 71b are interposed between the flanges 100FU and FL, the flange joint length in the water intrusion direction can be made longer than in the first embodiment. The invasion suppression effect can be further increased.
[0026]
In place of the thermistor, a temperature detector using a thermocouple may be employed. In this case, one end of the two detection lines is bonded to the negative electrode foil or the positive electrode foil inside the exterior material, and the detection line is laid between the bonding surfaces of the bonding flange and wired to the other end of the cell.
[0027]
-Third embodiment-
A third embodiment will be described with reference to FIGS. 11 is a plan view of both tab type cells 80, FIG. 12 is a view showing the inside of the tab type cells 80 with the upper exterior material removed, and FIGS. 13A to 13D are cross-sectional views of the respective parts of both tab type cells 80. FIG.
[0028]
The features of the both-tab type cell 80 of the third embodiment are as follows.
(1) As shown in FIGS. 11 and 12, the same voltage detection terminals 311b and 311c as those in the modification of the first embodiment are provided side by side with the positive and negative electrode tabs 1b and 1c.
(2) The detection wires 312b and 312c connected to the detection terminals 311b and 311c are wired between the flanges 100FU and 100FL.
(3) A thermistor (temperature detector) 70 is provided inside the battery, and the two + -detection wires 71a and 71b of the thermistor 70 are wired between the flanges 100FU and 100FL.
(4) A temperature detection terminal 72 is provided along with the negative electrode tab 1c.
[0029]
That is, one end of the negative electrode detection line 312c is joined to the negative electrode tab 1c. The other end of the negative electrode detection line 312c protrudes from the exterior material 100, and a tab 311c welded to the external connection portion is formed. As shown in FIGS. 13B and 13D, the detection line 312c is sandwiched between the flanges 100FU and 100FL and is routed in the battery longitudinal direction. The positive electrode detection line 312b whose one end is joined to the positive electrode tab 1b is similarly configured.
[0030]
Further, the thermistor 70 for detecting the temperature of the battery 80 is welded to the positive electrode foil 104 inside the exterior material 100, and the signal detection lines 71 a and 71 b of the thermistor 70 are routed to the negative electrode tab 1 c side to detect that the thermistor 70 is drawn to the exterior material 100. A temperature detection terminal 72 is provided at the tip of the wires 71a and 71b. As shown in FIGS. 13B and 13D, the detection lines 71a and 71b are sandwiched between the flanges 100FU and 100FL and routed in the battery longitudinal direction.
[0031]
Thus, according to the both tab type cell 80 of 3rd Embodiment, the following effects are obtained.
(1) Since the voltage detection terminals 312b and 312c are provided side by side with the positive and negative electrode tabs 1b and 1c, the assembled battery configured by laminating both tab type cells 80 in the opposite direction to each other. However, it is possible to concentrate the voltage detection lines on either side of the positive and negative electrode tabs. Therefore, the battery pack is reduced in size and wiring is simplified, and the cost is reduced.
(2) Since the thermistor 70 is joined to the positive electrode foil 104 inside the battery, and a temperature-dependent signal is taken out from the temperature detection terminal 72 outside the battery, the assembly is compared with the case where a temperature detector is provided outside the battery. The battery is downsized.
(3) The temperature detection lines 71a and 71b between the thermistor 70 and the temperature detection terminal 72 are wired between the flanges 100FU and 100FL. Therefore, the detection line routing portion between the flange joint surfaces serves as resistance when water enters from the flange joint surface, and the intrusion of moisture can be effectively suppressed. In the third embodiment, since the two detection lines 71a and 71b and the voltage detection line 312b are interposed between the flanges 100FU and FL, a water intrusion suppressing effect can be further obtained as compared with the second embodiment. .
[0032]
The present invention can be applied not only to the above-described sheet-like double tab type cell but also to a square cell as long as it is a double terminal type cell. In addition, the wet secondary battery in which the electrolyte solution and the internal electrode pair are vacuum-sealed in the laminate exterior material has been described, but the present invention is applicable to various thin secondary batteries in which positive and negative electrode tabs protrude from both ends of the cell. Can be applied. The present invention is not limited to the above-described embodiment as long as the above-described characteristic functions and effects can be obtained.
[Brief description of the drawings]
FIG. 1 is a top view showing a first embodiment of a tab-type cell according to the present invention. FIG. 2 is a side view of FIG. 1. FIG. 3 (a) is an enlarged cross section of a portion indicated by reference numeral III in FIG. FIG. 4B is a partially enlarged view thereof. FIG. 4 is a top view showing the inside after removing the upper exterior material of both tab-type cells. FIG. 5 is a cross-sectional view taken along the lines Va-Va and Vb-Vb in FIG. Vc-Vc cross-sectional view, Vd-Vd cross-sectional view [FIG. 6] (a) is a perspective view showing an example in which voltage detection lines are concentrated around one side of a plurality of stacked cells, and (b) is a connection of cells. FIGS. 7A and 7B are diagrams showing cells showing first and second modifications of the first embodiment. FIGS. 8A and 8B are diagrams showing a second of both tab type cells according to the present invention. 9 is a top view showing the embodiment. FIG. 9 is a view showing the inside of the cell according to the second embodiment. FIG. 10 is a cross-sectional view taken along the lines Xa-Xa, Xb-Xb, Xc-Xc, Xd- Xd cross section 【 11 is a top view showing a third embodiment of a both-tab type cell according to the present invention. FIG. 12 is a view showing the inside of the cell according to the third embodiment. FIG. 13 is a sectional view taken along line XIIIa-XIIIa in FIG. -XIIIb cross section, XIIIc-XIIIc cross section, XIIId-XIIId cross section [Explanation of symbols]
1, 50, 80: Both tab type cells 1b: Positive electrode tab 1c: Negative electrode tab 11b. 11c: Voltage detection terminal 12b, 312b: Positive voltage detection line 12c, 312c: Negative voltage detection line 70: Thermistor 71a, 71b: Temperature detection line 72: Temperature detection terminal 101: Internal electrode pair 101a: Positive electrode 101b: Negative electrode 101c : Separator 100FR: Upper exterior material flange 100FL: Lower exterior material flange 104: Positive electrode foil 104a: Positive electrode active material 104b: Insulating material 105: Negative electrode foil 105a: Negative electrode active material

Claims (4)

A bag-like exterior material formed by joining an internal electrode pair in which a positive electrode and a negative electrode are laminated and an electrolytic solution, and joining flanges provided on the entire circumference of a film-like upper exterior material and a lower exterior material. In both tab type cells in which the positive electrode tab and the negative electrode tab connected to the internal electrode pair extend in opposite directions to the outside of the exterior material ,
On at least one side of the positive and negative electrode tabs, a voltage detection terminal for detecting a voltage of a tab having a polarity opposite to the tab on the one side is provided ,
A voltage detection line having one end connected to the voltage detection terminal is wired between the joint flanges of the upper and lower exterior members, and the other end of the voltage detection line is the same as the tab of the opposite polarity. A both-tab type cell characterized in that it is bonded to a potential point . A bag-like exterior material formed by joining an internal electrode pair in which a positive electrode and a negative electrode are laminated and an electrolytic solution, and joining flanges provided on the entire circumference of a film-like upper exterior material and a lower exterior material. In both tab type cells in which the positive electrode tab and the negative electrode tab connected to the internal electrode pair extend in opposite directions to the outside of the exterior material,
One end is connected to the same potential as the positive electrode tab inside the exterior body, and the other end is sandwiched between flanges of the upper and lower exterior materials, and is connected to the negative electrode tab side, and a positive voltage detection line,
One end is connected to the same potential as the negative electrode tab inside the exterior body, and the other end has a negative voltage detection line that is sandwiched between the flanges of the upper and lower exterior materials and wired to the positive electrode tab side. Features both tab type cells. In both the tab type cells according to claim 2,
A temperature detector provided in the exterior body for detecting a cell temperature;
A double-tab type cell characterized in that a signal detection line of the temperature detector is routed to one of the positive and negative electrode tabs, and a temperature detection terminal is provided on the signal detection line. A plurality of both tab-type cells according to any one of claims 1 to 3, which are laminated,
A housing that houses a plurality of stacked tab-type cells;
A bus bar for electrically connecting a plurality of stacked tab-type cells in the housing;
A positive external terminal connected to a bus bar that is provided in the housing and connected to a bus bar that outputs a maximum voltage; and a negative external terminal connected to a bus bar that outputs a minimum voltage;
An assembled battery comprising: an external detection terminal provided in the housing and connected to the voltage detection terminal or the temperature detection terminal.

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